Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F285/00—Macromolecular compounds obtained by polymerising monomers on to preformed graft polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F265/00—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00
  • C08F265/04—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00 on to polymers of esters
  • C08F265/06—Polymerisation of acrylate or methacrylate esters on to polymers thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L27/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers
  • C08L27/02—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L27/04—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment containing chlorine atoms
  • C08L27/06—Homopolymers or copolymers of vinyl chloride
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
  • C08L51/003—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds

Definitions

• the present invention relates to a vinyl chloride polymer composition having an excellent workability.
• Vinyl chloride resins have been widely used in various fields due to their excellent physical and chemical properties.
• the vinyl chloride resins have various disadvantages from the viewpoint of workability. That is, vinyl chloride polymers have a high melt viscosity, a poor flowability, a narrow temperature range in which the resins can be converted to shaped products because the shaping temperature is close to the thermal decomposition temperature thereof, and a slow gelling rate.
• these resins are difficult to convert rapidly from a powdery state to a uniform molten state when being subjected to a roll milling procedure. This after results in a degraded surface appearance of the resultant shaped product.
• plasticizer is added to the vinyl chloride resin in order to eliminate the above--mentioned disadvantages.
• the use of the plasticizer creates some problems due to its volatility and also results in a decreased mechanical property of the resultant shaped products. Accordingly, the plasticizer is useless for producing a rigid polyvinyl chloride shaped product.
• various copolymers compatible . with the vinyl chloride resin are used as a processing aid to increase the gelling rate of the resin and to reduce the stickness thereof to a metal surface of the molding machine used, thereby increasing the productivity, to obtain a smooth surface of the resultant shaped product, to impart a uniform luster.to all the shaped products produced when the molding procedure is continuously carried out for a long period of time or to attain deep drawability in the resultant shaped product.
• Some of there copolymers are successful in some fields of application. Typical copolymers which are presently marketed are those which contain methyl methacrylate as a main component.
• copolymers are effective for promoting the gelling rate of the vinyl chloride resin and for increasing the tensile elongation at elevated temperatures of the resultant shaped product.
• these copolymers are disadvantageous in that an extruded film resulting from the vinyl chloride resin having incorporated therein these copolymers is deficient in luster and contains a non-gelled material (which is also referred to as fish eye).
• a non-gelled material which is also referred to as fish eye.
• the above-mentioned methyl methacrylate copolymers exhibit., in themselves, a high adnesion to a metal surface and has a high melt visc.osity.
• the use of the lubricant is disadvantageous in that the lubricant adheres to a surface of a mold during the molding procedure (this adhesion is also referred to as- plate out) and causes blooming on a surface of the resultant shaped product. Accordingly, the use of the lubricant in combination with the methyl,methacrylate copolymer is also ineffective for improving the workability of the vinyl chloride resin.
• the inventors of the present invention made extensive studies in consideration of the above mentioned problems. As a result of this, the inventors of the present invention succeeded in obtaining a vinyl chloride polymer composition exhibiting an excellent flowability and a lasting lubricating property and which is free from a plate-out phenomenon, while retaining excellent processing properties possessed by a vinyl chloride resin having incorporated therein a methyl methacrylate copolymer. Thus, the inventors of the present invention attained this invention.
• An object of the present invention is to.provide a vinyl chloride polymer composition exhibiting an excellent flowability and lubricity durability while retaining improved processing properties imparted by a polymethyl methacrylate and which composition causes no bleeding or plateout phenomenon during the molding procedure and is transparent.
• the vinyl chloride polymer composition of the present invention comprises:
• the vinyl chloride polymer composition of the present invention is characterized by the fact the polymeric ingredient (II), i.e. the three-stage polymerization product, has a sandwich structure comprising the polymer resulting from the first monomeric component (b) which serves to control the lubricating property of the composition, which polymer (b) is a low molecular weight acrylic ester polymer or copolymer of an acrylic ester and a methacrylic ester, on the inner and outer sides of which the methacrylate polymer components (a) and the polymer derived from the second monomeric component (c) highly compatible with the vinyl chloride polymer are disposed, respectively.
• the polymeric ingredient (II) i.e. the three-stage polymerization product
• This sandwich structure of the three-stage polymerization product is obtained by polymerizing an acrylic ester or a mixture of an acrylic ester and a methacrylic ester (the first monomeric component (b)), in the presence of a polymer or copolymer latex (the polymeric component (a)) comprising at least 50% by weight of methyl methacrylate, under conditions such that the polymerization product resulting from the first monomeric component (b) exhibits a reduced viscosity (nsp/c) of 1.0 or less, and then, by polymerizing methyl methacrylate or a mixture of methyl methacrylate and less than 50% by weight of at least one other copolymerizable monomer (the second monomeric component (c)) in the presence of the resultant latex comprising the components (a) and (b).
• the composition of the present invention comprises a polymeric ingredient '(1), that is, a vinyl chloride resin (I),having incorporated therein a polymeric ingredient (II), that is, a polymerization product (II) which is prepared in such a manner that the first monomeric component (b) is first polymerized on and attached to the outer side of the polymeric component (a), which is a starting constituent of the sandwich structure, the resultant outer portion of the first polymerization product exhibiting a high lubricating property and, then, the second monomeric component (c) is second polymerized on the outer side of the first polymerization product, the resultant outer portion of which is highly compatible with the vinyl chloride polymer (I).
• a polymeric ingredient '(1) that is, a vinyl chloride resin (I),having incorporated therein a polymeric ingredient (II), that is, a polymerization product (II) which is prepared in such a manner that the first monomeric component (b) is first polymerized on and attached to the outer side
• the composition of the present invention exhibits a lasting lubricating property essential for the processing of the vinyl chloride resin. Also, when the composition of the present invention is molded by a blowing method to form a bottle, no drawdown is observed.
• the polymeric component (a) exhibits a reduced viscosity (nsp/c) of 2.0 or more
• the presence of this high molecular weight methyl methacrylate is effective not only for obtaining the above mentioned improved effects, but also for increasing the gelling rate of the resultant resin composition and for enhancing the fabricating properties, such as tensile elongation at elevated temperatures, of the resultant shaped product.
• the polymeric component (a) exhibits a reduced viscosity (nsp/c) of less than 2.0
• the presence of this low molecular weight methyl methacrylate exhibiting an excellent dispersibility is effective for increasing the flowability of the resultant resin composition and for reducing the occurrence of fish eye, i.e. non-gelled material, in the resultant shaped product.
• the above mentioned outstanding effects could not be attained by the conventional vinyl chloride resin compositions.
• the first monomeric component (b) for providing the middle portion of the sandwich structure should consist of a member selected from the group consisting of (1).
• alkyl acrylates in which the alkyl group has 1 to 18 carbon atoms, (2) benzyl acrylate, (3) mixtures of two or more of the above-mentioned compounds and (4) monomeric mixture of 30% by weight or more of at least one member selected from the group consisting of alkyl acrylates in which the alkyl group has 1 to 18 carbon atoms and benzyl acrylate, and 70% by weight or less of at least one alkyl methacrylate in which the alkyl group has 1 to 18 carbon atoms.
• the first monomeric component (b) For instance, in the case where styrene incompatible with the vinyl chloride resin is contained the first monomeric component (b), bleeding and plateout tend to occur during the molding of the resultant resin composition, which results in an increase in deposit on a surface of the mold used during the molding procedure. Also, the resultant resin composition is limited in its lubricity durability.
• the polymeric ingredient (II) the polymer resulting from the second monomeric component (c), which polymer is highly compatible with the vinyl chloride polymer (I) and has a high glass transition temperature (Tg) ' is attached to the outer side of the first polymerization product.
• the present invention provides a polymer having a sandwich structure which is prepared by a three-step polymerization method and exhibits a combination of excellent workability and a lasting lubricating property due to the synergistic effect of the respective components (a), (b) and (c), particularly, of the methacrylic ester and acrylic ester constituting the component (b).
• the intended composition of the present invention is obtained by incorporating the polymer having the above mentioned structure and composition into the vinyl chloride resin.
• the sandwich structure of the polymer (II) is a very important requisite for enhancing the lubricating property or releasability from a metal surface of the vinyl chloride polymer composition and for preventing the polymer composition from causing a bleeding or plateout phenomenon. Even if the polymer (a), and the single polymers requlting from the monomeric components (b) and (c), respectively, are used or a polymer prepared by polymerizing the monomers of the components (a), (b) and (c) in a single step is used, the resultant polymer composition cannot exhibit an excellent lubricating property.
• a vinyl chloride polymer composition containing such polymer is inferior to the vinyl chloride polymer composition containing a polymer having the sandwich structure in respect to its releasability -from a metal surface and durability in lubricating property.
• the polymer (II) used in the composition of the present invention contains the polymeric component (a) in an amount of from 5 to 45 parts by weight, preferably, from 20 to 40 parts by weight, per 100 parts by weight of the polymer.
• the polymeric component (a) is greater than 45 parts by weight, the resultant composition exhibits a poor lubricating property and also a decreased durability in its lubricating property.
• the polymeric component (a) content less than 5 parts by weight in the polymer (II) deteriorates workability other than a lubricating property of the resultant composition and lowers the lubricity durability thereof.
• the resultant composition exhibits excellent fabricating properties and-lubricity durability.
• the reduced viscosity (nsp/c) of the polymeric component.(a) is less than 2.0, the resultant polymer (II) exhibits an excellent dispersibility in the vinyl chloride polymer (I) and the vinyl chloride polymer (I) with such polymer (II) dispersed therein exhibits an excellent flowability and lubricity durability.
• the polymeric component (a) is a polymethyl methacrylate or a copolymer comprising at least 50% by weight of methyl methacrylate.
• the comonomer for the methyl methacrylate is not particularly limited and may be any suitable ethylenically unsaturated monomer depending on the end use of the resultant composition.
• the comonomer may be at least one member selected from the group consisting of aromatic vinyl monomers, unsaturated nitriles, vinyl esters, acrylic esters and methacrylic esters other than methyl methacrylate.
• the polymeric component (a) may also contain a polyfunctional monomer such as divinyl benzene and allyl methacrylate. In this case, it is preferable that the polyfunctional monomer is used in an amount of 2.0% by weight or less.
• the first monomeric component (b) is used in an amount of from 40 to 70 parts by weight, preferably, from 50 to 60 parts by weight, per 100 parts by weight of the polymer.
• a component (b) content less than 40 parts by weight causes the resultant composition to exhibit a degraded lubricating property.
• a component (b) content exceeding 70 parts by weight in the polymer causes the resultant composition to exhibit degraded processing properties, such as poor surface- .property and luster.
• a remarkable feature of the first polymerization is that the monomeric component (b) is polymerized in a very small molecular weight.
• the first polymerization should be carried out under such a condition that a polymer resulting from the monomeric component (b) alone exhibits a reduced viscosity (nsp/c) of 1.0 or less, preferably, about 0.5 If the reduced viscosity (nsp/c) of the polymer exceeds 1.0, the lubricating effect thereof is lowered, which eventually results in a degraded lubricating property of the resultant polymer composition.
• the monomeric component (b) comprises 30 to 100% by weight of at least one acrylic ester and 0 to 70% by weight of at least one methacrylic ester.
• the resultant composition exhibits an excellent lubricating property, an enhanced releasability from a metal surface and a high extrusion rate, although the gelling rate thereof becomes slow.
• the content of the acrylic ester is less than 30% by weight, the resultant composition exhibits an extremely poor lubricating property.
• the acrylic ester usable for the first monomeric component (b) may be selected from the group consisting of ethyl acrylate, n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate.
• the methacrylic ester usable for the first monomeric component (b) may be selected from the group consisting of ethyl methacrylate, n-butyl methacrylate and 2-ethylhexyl methacrylate.
• acrylic and methacrylic esters monomers capable of producing a polymer having a low glass transition temperature, for example, n-butyl acrylate; 2-ethylhexyl acrylate, n-butyl methacrylate and 2-ethylhexyl methacrylate, are preferably used.
• the acrylic ester and the methacrylic ester of which the component (b) is composed should be polymerized in the form of a random copolymer. It is not preferable that the acrylic ester be allowed to graft onto the methacrylic ester and vice versa. That is, if the polymer resulting from the component (b) contains, for example, butyl acrylates linked to each other so as to form a block, the resultant polymer composition exhibits no transparency at all.
• the second monomeric component (c) is used in an amount of from 5 to 40 parts by weight, per 100 parts by weight of the polymer. If the amount of the component (c) is less than 5 parts by weight, the resultant composition cannot exhibit a satisfactory workability. In addition, such composition tends to undergo a secondary aggregation during the subsequent processes such as coagulation, dehydration and drying, which results in a poor productivity. Also, if the content of the component (c) is greater than 40 parts by weight, the resultant composition exhibits no lasting lubricating property.
• the component (c) may contain less than 50% by weight of any monomer copolymerizable with methyl methacrylate. However, in order to ensure that. the resultant composition exhibits an excellent flowability, it is preferable that the component (c) consists of a methyl methacrylate monomer only.
• the second polymerization may be carried out under any polymerization condition, to produce the polymer composition having a high lubricity durability which is an important feature of the present invention.
• the second polymerization procedure is preferably carried out under such a condition that a polymer from the second monomeric component (c) alone exhibits a reduced viscosity of more than 2.0.
• the second polymerization is carried out under such a polymerization condition that a polymerization product of the second monomeric component (c) alone exhibits a reduced viscosity of 2.0 or less.
• a polymethyl methacrylate fraction having an extremely high degree of polymerization and a high softening temperature, because this type of polymethyl methacrylate fraction has a poor dispersing property in the polymer composition of the present invention under the usual condition under which the vinyl chloride polymer composition is processed, and does not fuse at the usual shaping temperature.
• the polymer (II) is prepared by an emulsion polymerization method.
• any conventional emulsifying agent may be used.
• the polymerization initiator may be selected from water-soluble and oil-soluble sole type or redox type initiators.
• the reduced viscosity (nsp/c) of the polymer may be optionally adjusted by any conventional method, such as by using a chain transfer agent or by controlling the polymerization temperature.
• the polymer (II) thus prepared may be mixed with-the vinyl chloride polymer (I) by any conventional method.
• the vinyl chloride polymer composition thus prepared may have incorporated therein any additives such as stabilizers, lubricants, plasticizers, impact modifiers, coloring matters, fillers foaming agents and other processing additives.
• the present invention will be illustrated in more detail by the following examples.
• parts are by weight.
• the reduced viscosity (nsp/c) of polymer was determined from a calibration curve which had been previously plotted in terms of sp/c versus amount of n-octyl mercaptan on each monomer composition.
• a reaction vessel having a stirrer and a reflux condenser was charged with a mixture of 280 parts of deionized water, 1.5 parts of sodium dioctyl sulfosuccinate, 0.2 parts of ammonium persulfate, and, 30 parts of methyl methacrylate and 0.003 parts of n-octyl mercaptan. After the atmosphere within the vessel was replaced with nitrogen, the mixture was heated to a temperature of 65°C under stirring and that temperature was maintained for 2 hours while stirring the mixture, to provide a polymeric component (a).
• a first monomeric component (b) consisting of a mixture of 30 parts of n-butyl methacrylate, 20 parts of n-butyl acrylate, and 0.5 parts of n-octyl mercaptan, was added dropwise to the polymerization mixture in the vessel for one hour.
• the resultant mixture was stirred at a temperature of 65°C for 2 hours to carry out the first polymerization.
• a second monomeric component (c) consisting of a mixture of 20 parts of methyl methacrylate and 0.002 parts of n-octyl melcaptan was added to the above-prepared polymerization mixture over 30 minutes.
• the resultant polymerization mixture was stirred at a temperature of 65°C for 2 hours so as to effect the second polymerization.
• aluminum chloride was added to the emulsion to cause the polymer to be salted out. Subsequently, the salted-out polymer was filtered, washed and dried. A polymer (II) was obtained.
• a predetermined amount parts of the polymer (II) was mixed with 100 parts of a polyvinyl chloride resin (I) having an average degree of polymerization of 715, 2.0 parts of dibutyl tin mercapto, 1.0 part of an epoxy type stabilizer, 0.5 parts of dibutyl tin maleate and 0.3 parts of a lubricant in a Henschel mixer, so that a vinyl chloride polymer composition was prepared.
• the processing properties of the resultant polymer composition are shown in Table 1.
• a polymer was prepared according to the same procedures as those described in Example 1, except that the n-octyl mercaptan was used in an amount of 0.05 parts in the polymeric component (a)-preparing procedure and in an amount of 0.03 parts in the second polymerization procedure.
• a polymer was prepared according to the same procedures as those described in Example 1, except that the monomeric component (b) consisted of 30 parts of styrene, 20 parts of n-butyl acrylate and 0.5 parts of n-octyl mercaptan.
• Example 2 The same reaction vessel as that described in Example 1 was charged with a mixture of 280 parts of deionized water, 1.5 parts of sodium dioctyl sulfosuccinate, 0.2 parts of ammonium persulfate, and a monomeric component (b) consisting of 30 parts of butyl methacrylate, 20 parts of butyl acrylate and 0.5 parts of n-octyl mercaptan. After the atmosphere within the vessel was replaced with nitrogen, the mixture was heated to a temperature of 65°C under stirring and that temperature was maintained for 2 hours while stirring the mixture.
• a monomeric component (b) consisting of 30 parts of butyl methacrylate, 20 parts of butyl acrylate and 0.5 parts of n-octyl mercaptan.
• a monomeric component (c) consisting of a mixture of 50 parts of methyl methacrylate and 0.005 parts of n-octyl mercaptan was added to the reaction system over 30 minutes. After the addition was complete, the resultant mixture was stirred for 2 hours at a temperature of 65°C to effect the polymerization. After the polymerization reaction, the same procedures as those described in Example 1 were applied to the resultant emulsion. Thus, a polymer was obtained.
• a polymer was prepared according to the same procedures as those described in Example 1, except that a polymeric component (a) was prepared from an admixture consisting of a mixture of 20 parts of methyl methacrylate and 0.002 parts of n-octyl mercaptan, and another mixture of 30 parts of methyl methacrylate and 0.003 parts of n-octyl mercaptan, and no monomeric component (c) was used.
• a reaction vessel was charged with a mixture of 280 parts of deionized water, 1.5 parts of sodium dioctyl sulfosuccinate, 0.2 parts of ammonium persulfate, 80 parts of butyl methacrylate, 20 parts of butyl acrylate and 1.2 parts of n-octyl mercaptan. After the atmosphere within the vessel was replaced with nitrogen, the mixture was heated to a temperature of 65°C and that temperature was maintained for 2 hours while stirring the mixture, so as to effect the polymerization. After the polymerization reaction, the same procedures as those described in Example 1 were applied to the resultant emulsion. Thus, a polymer was obtained.
• Table 1 Comparison Example 5 relates to the vinyl chloride polymer alone.
• a polymer (II) was prepared according to the same procedures as those described in Example 1, except that the polymeric component (a) was prepared from 30 parts of methyl methacrylate, the monomeric component (b) consisted of 25 parts of ethyl methacrylate and 25 parts of butyl acrylate, the monomeric component (c) consisted of 20 parts of methyl methacrylate, and the nsp/c of the polymeric component (a) and polymers resulting from the respective monomeric components (b) and (c) was adjusted to a value as shown in Table 2 by using varying amounts of n-octyl mercaptan.
• a predetermined amount of the resultant polymer was mixed with 100 parts of a polyvinyl chloride resin having an average degree of polymerization of 715, 2.0 parts of dibutyl tin mercapto, 1.0 part of an epoxy type stabilizer, 0.5 parts of a dibutyl tin maleate and 0.3 parts of a lubricant, so as to form a vinyl chloride resin composition.
• a polymer (II) was prepared according to the same procedures as those described in Example 1,,except that the monomeric component (b) consisted of 30 parts of ethyl methacrylate and 20 parts of n-butyl acrylate, the monomeric component (c) consisted of the compounds shown in Table 3 and the polymeric component (a) was prepared from the monomers shown in Table 3, and n - octyl mercaptan was added in an amount indicated in Table 3.
• Table 3 clearly indicates that even if the monomeric components (b) and (c) are used in amounts within the range defined by the present invention, when n-butyl acrylate which is a comonomer for the methyl methacrylate used for preparing the polymeric component (a) exceeds 50%, the resultant composition exhibits a substantially inferior stickness (i.e. lubricity durability) to that of the composition of Example 8. Also, Table 3 clearly indicates that even if the components (a) and (b) are used in amounts within the range defined by the present invention, when the butyl acrylate in the component (c) exceeds 50%, the resultant composition exhibits a substantially inferior stickiness to that of the composition of Example 10.
• a vinyl chloride resin composition was prepared according to the same formulation as that described in Example 3. The processing properties of the resultant compositions were determined. The results are shown in Table 4.
• Table 4 clearly indicates that the ethyl methacrylate in the component (b) (Comparison Example 10) and the methyl methacrylate in the component (b) (Comparison Example 11) are, respectively, greater than 70%, the resultant compositions exhibit a substantially decreased roll lubricating property and stickiness.

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• 1980
  • 1980-05-20 JP JP6689380A patent/JPS56163139A/ja active Granted
• 1981
  • 1981-05-19 DE DE8181302218T patent/DE3172694D1/de not_active Expired
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